This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A259861 #12 Jun 21 2017 00:25:05 %S A259861 2,2,-5,-29,-70,-70,169,985,2378,2378,-5741,-33461,-80782,-80782, %T A259861 195025,1136689,2744210,2744210,-6625109,-38613965,-93222358, %U A259861 -93222358,225058681,1311738121,3166815962,3166815962,-7645370045,-44560482149,-107578520350,-107578520350 %N A259861 a(n+8)+34*a(n+4)+a(n)=0 with a(0)-a(7) as shown. %H A259861 Colin Barker, <a href="/A259861/b259861.txt">Table of n, a(n) for n = 0..1000</a> %H A259861 J. Riordan, <a href="http://www.jstor.org/stable/2005477">The distribution of crossings of chords joining pairs of 2n points on a circle</a>, Math. Comp., 29 (1975), 215-222. %H A259861 J. Riordan, <a href="/A003480/a003480.pdf">The distribution of crossings of chords joining pairs of 2n points on a circle</a>, Math. Comp., 29 (1975), 215-222. [Annotated scanned copy] %H A259861 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4,-8,4,-1). %F A259861 G.f.: -(x^3-3*x^2+6*x-2) / (x^4-4*x^3+8*x^2-4*x+1). - _Colin Barker_, Jul 09 2015 %o A259861 (PARI) Vec(-(x^3-3*x^2+6*x-2)/(x^4-4*x^3+8*x^2-4*x+1) + O(x^50)) \\ _Colin Barker_, Jul 09 2015 %Y A259861 Cf. A259860. %K A259861 sign,easy %O A259861 0,1 %A A259861 _N. J. A. Sloane_, Jul 08 2015